Integrated valve device

ABSTRACT

An integrated valve device includes a casing having intake passages respectively accommodating valves and separately connected with cylinders of an engine. The valves are skewered with a shaft extending through a through hole of each valve along a rotation axis. An actuator generates driving force to rotate the valves via the shaft. The shaft has a fitting portions respectively supporting the valves at mount angles. The mount angle of each valve with respect to each fitting portion is determined correspondingly to load torque applied to each valve toward a valve-open direction when being in a full close position.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based on and incorporates herein by reference Japanese Patent Application No. 2006-219559 filed on Aug. 11, 2006.

FIELD OF THE INVENTION

The present invention relates to an integrated valve device having multiple valves for an internal combustion engine.

BACKGROUND OF THE INVENTION

For example, GB 2 391 907 A (JP-A-2004-060525) discloses an integrated valve device provided in an intake manifold of an internal combustion engine. The integrated valve device includes multiple valves connected via one shaft. For example, U.S. Pat. No. 6,979,130 B1 (JP-A-2003-509634) discloses an integrated valve device provided in an intake manifold of an internal combustion engine. The integrated valve device includes multiple valve units axially connected to define a predetermined distance adjacently therebetween. Each of the valve units includes one housing and one valve.

Each of the integrated valve devices of GB 2 391 907 A and U.S. Pat. No. 6,979,130 B1 includes the valves each integrally formed of resin. Each valve has a valve shaft as a rotation center, and has a through hole. The through hole axially extends.

Each of the integrated valve devices of GB 2 391 907 A and U.S. Pat. No. 6,979,130 B1 includes a shaft having a cross section in a polygonal shape. The shaft is inserted into the through hole of each valve. In this structure, the valves are skewed with the shaft. Each through hole also has a cross section in a polygonal shape, correspondingly to the cross section of the shaft. In this structure, rotation of the valves relative to the shaft is restricted in a condition where the shaft is inserted into the through holes of the valves. Each valve is, for example, a butterfly valve having a plate-shaped valve members radially extending from the valve shaft toward radially both ends.

Each of the integrated valve devices of GB 2 391 907 A and U.S. Pat. No. 6,979,130 B1 includes the valves connected by being skewed with the shaft. In this structure, one end of the shaft, which extends from the fitting portions respectively connected with the valves, is preferably provided with a stopper portion. The stopper portion of the shaft makes contact with a full close stopper provided to an intake manifold when the valves are in the full close position, so that all the valves are positioned at the predetermined full close position. When the valves are in the full close position, the valves respectively define openings producing a predetermined amount of intake air therethrough.

The intake manifold of the engine includes an actuator for simultaneously manipulating the positions of all the valves. The shaft has one axial end connected with an output shaft of the actuator via a coupling member. In this structure, the coupling member needs a predetermined gap relative to the output shaft for smoothly transmitting driving force of a power source such as an electric motor of the actuator. The shaft and the coupling member may rattle due to defining the gap between the coupling member and the output shaft.

In particular, when the intake manifold is transmitted with vibration of the engine and/or pulsation in pressure of intake air passing through the intake pipe of the engine, the coupling member intensively rattle to repeat collision and friction between the coupling member and the output shaft. As a result, a fitting surface of the coupling member may be abnormally abraded away.

Therefore, a spring is preferably provided to an axial end of the shaft on the opposite side of the actuator. The spring is capable of reducing the gap between the coupling member and the output shaft in order to suppress the play caused in the coupling member.

However, in each of the integrated valve devices of GB 2 391 907 A and U.S. Pat. No. 6,979,130 B1, when the valves are in the full close position under operation of the engine, intake air applies negative pressure to the surface of each of the valves. In this condition, each valve is applied with bending moment, which is caused by load torque, around the valve shaft of each valve toward the valve-open direction. The shaft has fitting portions each supporting each valve. The fitting portions are twisted correspondingly to the load torque. Dissimilarly to the structures of GB 2 391 907 A and U.S. Pat. No. 6,979,130 B1, when the integrated valve device has a cantilever structure, and the valve shaft is provided eccentrically on one side of each valve member, the torsion caused in the fitting portions of the shaft becomes significantly large.

When the spring is provided for applying force to the shaft in order to reduce the play therein, the spring applies load torque to the valves and produces bending moment around the valve shaft toward the valve-open direction. Thus, the shaft is twisted correspondingly to the load torque.

When the valves being in the full close position are applied with load torque toward the valve-open direction and the shaft is twisted, the fitting portions are respectively twisted at torsion angles different from each other. In this condition, the angular positions of the valves deviate from each other, and consequently, opening areas in the intake passages respectively connecting with the intake ports of the cylinders of the engine deviate from each other. Consequently, the angular positions of the valves, which are in the full close position, widely vary from each other. As a result, the amount of intake air varies among the cylinders, and leakage of intake air also varies among the cylinders.

As the distance from the stopper portion, which limits the full close position of the valves, becomes large, the torsion angles of the fitting portions become large. As the distance from the stopper portion becomes large, the opening area of the valve becomes rage, compared with a reference opening area of the valve in the most vicinity of the stopper portion. Consequently, as the distance from the stopper portion becomes large, leakage of intake air flow becomes large. As a result, the engine performance is decreased.

Variation in the torsion angles of the fitting portions of the shaft needs to be reduced in order to reduce variation in the opening areas of the valves of the cylinders of the engine. Rigidity of the shaft may be enhanced by increasing the diameter thereof, in order to reduce the torsion therein. However, in this case, the through holes of the valves also become large, and consequently, the valve shafts respectively defining the through holes also become large. As a result, manufacturing cost of the valves increase.

In addition, weight of the valve and the shaft become large, and consequently, vibration resistance of the valves becomes low. In this case, when the intake manifold is transmitted with vibration of the engine and/or pulsation in pressure of intake air passing through the intake pipe of the engine, the valves intensively rattle to repeat collision and friction against the intake manifold. As a result, the valves and the intake manifold may be abnormally abraded away.

SUMMARY OF THE INVENTION

In view of the foregoing and other problems, it is an object of the present invention to produce an integrated valve device being capable of absorbing variation in opening areas of valves respectively provided to cylinders of the engine, when the valves are in a full close position.

According to one aspect of the present invention, an integrated valve device for and internal combustion engine, the integrated valve device including a casing having a plurality of intake passages separately connected with a plurality of cylinders of the internal combustion engine. The integrated valve device further includes a plurality of valves each being provided to each of the plurality of intake passages, the plurality of valves each having a through hole extending along a rotation axis. The integrated valve device further includes a shaft extending through the through hole along the rotation axis, the plurality of valves being skewered with the shaft. The integrated valve device further includes an actuator for generating driving force to rotate the plurality of valves via the shaft toward one of a valve-open direction and a valve-close direction.

The shaft has a plurality of fitting portions respectively supporting the plurality of valves. Each of the plurality of valves is at a mount angle with respect to each of the plurality of fitting portions. The mount angle is determined correspondingly to load torque applied to each of the plurality of valves toward the valve-open direction when being in a full close position.

According to another aspect of the present invention, an integrated valve device for and internal combustion engine, the integrated valve device including a casing having a plurality of intake passages separately connected with a plurality of cylinders of the internal combustion engine. The integrated valve device further includes a plurality of valves each being provided to each of the plurality of intake passages, the plurality of valves each having a through hole extending along a rotation axis. The integrated valve device further includes a shaft extending through the through hole along the rotation axis, the plurality of valves being skewered with the shaft. The integrated valve device further includes an actuator for generating driving force to rotate the plurality of valves via the shaft toward one of a valve-open direction and a valve-close direction. The shaft has a plurality of fitting portions respectively supporting the plurality of valves at mount angles. Each of the plurality of valves includes a valve shaft and a valve member. The valve shaft is in a substantially cylindrical shape defining the through hole. The valve member is in a substantially plate shape and radially extends from the valve shaft perpendicularly to the rotation axis. The valve member of each of the plurality of valves has rigidity, which is determined correspondingly to load torque applied to each of the plurality of valves toward the valve-open direction when being in a full close position.

According to another aspect of the present invention, an integrated valve device for and internal combustion engine, the integrated valve device including a casing having a plurality of intake passages separately connected with a plurality of cylinders of the internal combustion engine. The integrated valve device further includes a plurality of valves each being provided to each of the plurality of intake passages, the plurality of valves each having a through hole extending along a rotation axis. The integrated valve device further includes a shaft extending through the through hole along the rotation axis, the plurality of valves being skewered with the shaft. The integrated valve device further includes an actuator for generating driving force to rotate the plurality of valves via the shaft toward one of a valve-open direction and a valve-close direction. The shaft has a plurality of fitting portions respectively supporting the plurality of valves at mount angles. Each of the plurality of valves includes a valve shaft and a valve member. The valve shaft is in a substantially cylindrical shape defining the through hole. The valve member is in a substantially plate shape and radially extends from the valve shaft perpendicularly to the rotation axis. The valve member has an end surface on an opposite side of the valve shaft. The end surface of the valve member has a notch to define an opening portion for generating vortex flow in intake air flowing to the cylinders of the internal combustion engine. The opening portion of each of the plurality of valve members has an opening area, which is determined correspondingly to load torque applied to each of the plurality of valve members toward the valve-open direction when being in a full close position.

According to another aspect of the present invention, an integrated valve device for and internal combustion engine, the integrated valve device including a casing having a plurality of intake passages separately connected with a plurality of cylinders of the internal combustion engine. The integrated valve device further includes a plurality of valves each being provided to each of the plurality of intake passages, the plurality of valves each having a through hole extending along a rotation axis. The integrated valve device further includes a shaft extending through the through hole along the rotation axis, the plurality of valves being skewered with the shaft. The integrated valve device further includes an actuator for generating driving force to rotate the plurality of valves via the shaft toward one of a valve-open direction and a valve-close direction. The shaft has a plurality of fitting portions respectively supporting the plurality of valves at mount angles. Each of the plurality of valves includes a valve shaft and a valve member. The valve shaft is in a substantially cylindrical shape defining the through hole. The valve member is in a substantially plate shape and radially extends from the valve shaft perpendicularly to the rotation axis. The casing has a plurality of cylindrical portions each defining therein each of the plurality of intake passages. Each of the plurality of cylindrical portions has a wall surface defining a protrusion in the vicinity of the valve member being in a full close position. The protrusion extends to reduce a cross section of each of the plurality of intake passages, and has a tip end defining an opposed surface being faced to an end surface of the valve member being in the full close position. The opposed surface of the protrusion is at a distance from a rotation center of each of the plurality of valve members. The distance is determined correspondingly to load torque applied to each of the plurality of valve members toward the valve-open direction when the plurality of valve members is in the full close position.

According to another aspect of the present invention, an integrated valve device for and internal combustion engine, the integrated valve device including a casing having a plurality of intake passages separately connected with a plurality of cylinders of the internal combustion engine. The integrated valve device further includes a plurality of valves each being provided to each of the plurality of intake passages, the plurality of valves each having a through hole extending along a rotation axis. The integrated valve device further includes a shaft extending through the through hole along the rotation axis, the plurality of valves being skewered with the shaft. The integrated valve device further includes an actuator for generating driving force to rotate the plurality of valves via the shaft toward one of a valve-open direction and a valve-close direction. The shaft has a plurality of fitting portions respectively supporting the plurality of valves at mount angles. Each of the plurality of valves includes a valve shaft and a valve member. The valve shaft is in a substantially cylindrical shape defining the through hole. The valve member is in a substantially plate shape and radially extends from the valve shaft perpendicularly to the rotation axis. The valve member of each of the plurality of valves has an end surface on an opposite side of the valve shaft. The valve member has a protrusion in the vicinity of the end surface. The protrusion is in a substantially arc shape along a locus of the valve member being rotatable. The valve member has a valve surface on a side of the valve shaft with respect to the protrusion. The protrusion of the valve member extends toward the valve-close direction relative to the valve surface. The protrusion has a length with respect to the valve-close direction. The length of the protrusion is determined correspondingly to a maximum angle of torsion caused in the shaft by load torque applied to the plurality of valves toward the valve-open direction when being in the full close position.

According to another aspect of the present invention, an integrated valve device for and internal combustion engine, the integrated valve device including a casing having a plurality of intake passages separately connected with a plurality of cylinders of the internal combustion engine. The integrated valve device further includes a plurality of valves each being provided to each of the plurality of intake passages, the plurality of valves each having a through hole extending along a rotation axis. The integrated valve device further includes a shaft extending through the through hole along the rotation axis, the plurality of valves being skewered with the shaft. The integrated valve device further includes an actuator for generating driving force to rotate the plurality of valves via the shaft toward one of a valve-open direction and a valve-close direction. The shaft has a plurality of fitting portions respectively supporting the plurality of valves at mount angles. Each of the plurality of valves includes a valve shaft and a valve member. The valve shaft is in a substantially cylindrical shape defining the through hole. The valve member is in a substantially plate shape and radially extends from the valve shaft perpendicularly to the rotation axis. The casing has a plurality of cylindrical portions each defining therein each of the plurality of intake passages. Each of the plurality of cylindrical portions has a wall surface defining each of the plurality of intake passages. The wall surface defines an opposed surface being faced to an end surface of the valve member being in the full close position. The opposed surface of each of the plurality of cylindrical portions extends to an upstream of an intake air along the valve-open direction. The opposed surface is in a substantially arc shape along a locus of the valve member being rotatable. The opposed surface has a length with respect to the valve-open direction. The length of the opposed surface is determined correspondingly to a maximum angle of torsion caused in the shaft by load torque applied to the plurality of valves toward the valve-open direction when being in the full close position.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings. In the drawings:

The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings. In the drawings:

FIG. 1 is a sectional view showing a valve member and a valve shaft of an integrated valve device, according to a first embodiment;

FIG. 2 is a sectional view showing a valve unit including the valve member and the valve shaft, according to the first embodiment;

FIG. 3 is a perspective view showing the integrated valve device serving as an intake vortex generator, according to the first embodiment;

FIG. 4 is a sectional view showing the integrated valve device, according to the first embodiment;

FIG. 5 is a sectional view taken along with the line V-V in FIG. 4, according to the first embodiment;

FIG. 6 is a partially sectional view showing a connection between a pin rod and an actuator via a stopper lever of the pin rod and a shaft and a coupling member of the actuator, according to the first embodiment;

FIG. 7A is a side view showing the pin rod, FIG. 7B is a sectional view taken along the line VIIB-VIIB in FIG. 7A, and FIG. 7C is a sectional view taken along the line VIIC-VIIC in FIG. 7A, according to a second embodiment;

FIG. 8 is a sectional view showing a valve unit including the valve member and the valve shaft, according to a third embodiment;

FIG. 9 is a sectional view showing a valve unit, according to a fourth embodiment;

FIG. 10 is a perspective view showing the valve unit, according to the fourth embodiment;

FIG. 11 is a sectional view showing a valve unit, according to a fifth embodiment; and

FIGS. 12A, 12B are sectional views each showing main components of a valve unit, according to a sixth embodiment.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS First Embodiment

An intake air control apparatus shown in FIGS. 1 to 6 is provided to a multicylinder internal combustion engine 500 such as a four-cylinder engine of a vehicle. The intake air control apparatus is provided with an intake vortex generator capable of generating vertical vortex flow (tumble flow) in each cylinder of the multicylinder engine for facilitating combustion of mixture gas. The intake vortex generator is provided to an integrated valve device constructed of multiple valves 1 to 4 arranged in an intake manifold 5 along a pin rod (shaft) 9 that extends to define a rotative direction of the valves 1 to 4. The valves 1 to 4 are arranged in parallel with each other, and are distant from each other by a predetermined distance. The valves 1 to 4 are formed of, for example, resin to serve as an intake control valve. The intake manifold 5 serves as a common casing of the multiple valves 1 to 4.

The engine 500 has combustion chambers supplied with mixture gas of intake air and fuel, and generates thermal energy by burning mixture gas of intake air and fuel in the combustion chambers, so that the engine 500 produces output power. The engine 500 includes an intake duct (intake pipe) for supplying intake air into each combustion chamber of each cylinder of the engine 500. The engine 500 further includes an exhaust duct (exhaust pipe) to discharge exhaust gas from each combustion chamber to the outside through a purification device.

The intake duct includes an air cleaner case, a throttle body, a surge tank, and an intake manifold 5. The air cleaner case accommodates an air cleaner for filtrating intake air. The throttle body is provided downstream of the air cleaner case with respect to intake air flow. The surge tank is provided downstream of the throttle body. The intake manifold 5 is provided downstream of the surge tank. The intake manifold 5 has a double-pipe structure.

The intake manifold 5 includes multiple polygonal cylindrical portions 6 and multiple housings 7. The polygonal cylindrical portions 6 respectively have first to fourth fitting holes therein. The housings 7 respectively have first to fourth intake passages therein. The intake manifold 5 serves as an intake manifold pipe through which intake air flows into the polygonal cylindrical portions 6. The polygonal cylindrical portions 6 respectively define intake passages 11, 12 therein. The intake air is distributed to each intake port of each cylinder of the engine 500. The intake port is provided to a cylinder head 8 of the engine 500.

In this embodiment, the polygonal cylindrical portion 6 of the intake manifold 5 define the first to fourth fitting holes 14 for respectively accommodating valve units therein. The polygonal cylindrical portions 6 have multiple partition walls for airtightly partitioning adjacent two fitting holes 14 therebetween. Specifically, one of the partition walls of the polygonal cylindrical portions 6 partitions the first fitting hole 14 from the second fitting hole 14, the second fitting hole 14 from the third fitting hole 14, or the third fitting hole 14 from the fourth fitting hole 14.

The intake manifold 5 has shaft through holes 15 extending straight from the leftmost sidewall of the cylindrical portions 6 to the rightmost sidewall of the cylindrical portions 6 in FIG. 4. The shaft through holes 15 extend perpendicularly to the flow direction of intake air passing through the intake passages 12. That is, the shaft through holes 15 extend along a rotation shaft horizontally arranged in FIG. 4. The shaft through holes 15 extend through all the fitting holes 14 and all the polygonal cylindrical portions 6.

The cylindrical portions 6 define the intake passages 11 therein, upstream of the fitting holes 14 of the intake manifold 5. Each intake passage 11 is connected with each cylinder of the engine 500. The cylindrical portions 7 define intake passages 12 therein respectively to the cylinders of the engine 500. The intake passages 11, 12 are individually connected respectively with the intake ports 13 of the cylinders of the engine 500.

The engine 500 includes the cylinder head 8 and a cylinder block (not shown). The cylinder head 8 is airtightly connected with the downstream end of an intake duct. The cylinder block has a combustion chamber to which mixture gas flows from an intake port 13. The intake ports 13 define three-dimensional intake passages in the cylinder head 8. The cylinder head 8 is provided with sparkplugs (not shown) each having a tip end being exposed to the combustion chamber of each cylinder. The cylinder head 8 is mounted with injectors (solenoid injection valve) 8 each adapted to injecting fuel into each intake port 13 of each cylinder of the engine 500.

One side of the cylinder head 8 defines multiple intake ports 13 respectively opened and closed using poppet-type intake valves. The other side of the cylinder head 8 defines multiple exhaust ports (not shown) respectively opened and closed using poppet-type exhaust valves. The upstream of the cylinder head 8 defines recesses 16. That is, the cylinder head 8 defines the recesses 16 on the side of the intake manifold. Each of the recesses 16 has the depth equivalent to the thickness of each of the valves 1 to 4 in each valve unit. The cylinder head 8 has a connection end surface, which is in a rectangular loop shape, opposed to a connection end surface of the intake manifold 5.

A gasket 17 is provided between the cylinder head 8 and the intake manifold 5. The gasket 17 seals an annular gap between the connection end surface of the intake manifold 5 and the connection end surface of the cylinder head 8. The gasket 17 is a rectangular loop-shaped elastic member formed of an oil-resistive rubber material such as chloroprene rubber (CR) and nitrile-butadiene rubber (NBR).

The intake passage (first intake passage) 11, 12 and the intake port (first intake port) 13 are separately connected to the first cylinder #1, and are opened and closed using the valve 1. The intake passage (second intake passage) 11, 12 and the intake port (second intake port) 13 are separately connected to the second cylinder #2, and are opened and closed using the valve 2. The intake passage (third intake passage) 11, 12 and the intake port (third intake port) 13 are separately connected to the third cylinder #3, and are opened and closed using the valve 3. The intake passage (fourth intake passage) 11, 12 and the intake port (fourth intake port) 13 are separately connected to the fourth cylinder #4, and are opened and closed using the valve 4.

The order of the first to fourth cylinders #1 to #4 may be the same as the order of injection of the injectors respectively provided to the cylinders of the engine 500. Alternatively, the order of the first to fourth cylinders #1 to #4 may be different from the order of injection of the injectors.

In this embodiment, the intake vortex generator is an intake control valve module constructed of the valve units each having the resin housing rotatably accommodating the resin valve. The valve units are respectively provided in the fitting holes 14 of the intake manifold 5, and are arranged along the pin rod 9. The valve units are separated from each other at a regular distance. The number of the valve units corresponds to the number of the cylinders of the engine 500. The valve units are provided correspondingly to the intake ports 13 of the cylinders of the engine 500. In this embodiment, the valve units are arranged from the tip end of the pin rod 9 toward the rear end of the pin rod 9, in order, along the insertion direction of the pin rod 9.

The valve units include the valves 1 to 4, an actuator 10, and the housings 7. Each of the valves 1 to 4 is rotatably accommodated in each fitting hole 14 of the intake manifold 5. The actuator 10 is adapted to simultaneously manipulating all the valves 1 to 4 via the single pin rod 9. Each of the housings 7 internally define the intake passage 12 being opened and closed using each of the valves 1 to 4.

The housings 7 are integrally formed of a resin material such as grass fiber reinforced thermoplastic to be in a rectangular shape. Each housing 7 is elastically supported in each fitting hole 14 of the intake manifold 5 via two gaskets 18, 19. The gaskets 18, 19 serve to tightly seal the annular gap between the wall surface defining each fitting hole 14 in the intake manifold 5 and the outer periphery of each housing 7. The gaskets 18, 19 also serve to damp vibration transmitted from the engine 500 to each housing 7 via the intake manifold 5. Each of the gaskets 18, 19 is a rectangular loop-shaped elastic member formed of an oil-resistive rubber material such as chloroprene rubber (CR) and nitrile-butadiene rubber (NBR).

Each valve unit has each housing 7 connected with each intake passage 11 of the intake manifold 5. Each valve unit has each of the first to fourth intake passages 12 correspondingly connected with each intake port 13 of the cylinder head 8. Each housing 7 therein defines the intake passage 12 in a substantially rectangular shape. The intake passages 12 are located downstream of the intake passages 11 of the intake manifold 5, and are respectively communicated with the combustion chambers of the cylinders of the engine 500.

The outer periphery of each housing 7 defines reinforcing ribs 20 each extending circumferentially on the housing 7 or in parallel with the intake air flow. The reinforcing ribs 20 may not be provided.

Each housing 7 is a polygonal cylindrical member accommodating each of the valves 1 to 4 adapted to opening and closing the passage in each housing 7. Each housing 7 defines the polygonal cylindrical member on the inner side of the intake manifold 5 having a double-pipe structure.

Each housing 7 has upper and lower wall portions 21, 22 on the upper and lower sides. The upper and lower wall portions 21, 22 are opposed relative to a vertical direction perpendicular to the intake air flow passing along the axial direction of the intake passage 12. Each housing 7 has left and right wall portions 23, 24 on the left and right sides. The left and right wall portions 23, 24 are opposed relative to a horizontal direction perpendicular to the intake air flow passing along the axial direction of the intake passage 12.

The surface of the upper wall portion 21 and the surface of the lower wall portion 22 are opposed to each other to define the intake passage 12 therebetween. The surface of the left wall portion 23 and the surface of the right wall portion 24 are opposed to each other to define the intake passage 12 therebetween.

The length of each of the upper and lower wall portions 21, 22 are less than the length of each of the left and right wall portions 23, 24. Alternatively, the length of each of the upper and lower wall portions 21, 22 may be greater than the length of each of the left and right wall portions 23, 24. Each housing 7 has four corners each having a chamfer being in an arc shape or an R shape. Each of the four corners of each housing 7 may be in a square shape.

The left and right wall portions 23, 24 of the housing 7 respectively define cylindrical bearing portions opposed to each other via the intake passage 12. Each bearing portion has a bearing hole 25 rotatable relative to a valve shaft provided to each of the valves 1 to 4.

The intake passage 12 has the center axis passing through the center of the intake passage 12 horizontally in FIG. 12. Each bearing portion and each bearing hole 25 are offset toward the lower wall portion 22 of the housing 7 with respect to the center axis of the intake passage 12. Each bearing portion and each bearing hole 25 are offset toward the upstream of the intake air with respect to the center of the intake passage 12. Each bearing portion and each bearing hole 25 are located in the vicinity of the upstream opening of each housing 7, and are located in the vicinity of the lower wall portion 22 of each housing 7.

Two bearings 26, 27 are fitted, e.g., press-inserted to the inner periphery of each bearing hole 25 of each bearing portion. The bearings 26, 27 are integrally formed of a resin material or a metallic material to be in substantially cylindrical shapes. A valve shaft is provided to each of the valves 1 to 4. Each of the bearings 26, 27 has a sliding hole slidable relative to one of both ends of each valve shaft of each of the valves 1 to 4.

As shown in FIGS. 3 to 6, the actuator 10 is an electric actuator having a power unit constructed of an electric motor (not shown) and a transmission device such as reduction gears (not shown). The electric motor generates output torque when being supplied with electricity. The transmission device transmits rotation of a motor shaft of the electric motor to the pin rod 9.

The electric motor may be a DC motor such as a brushless motor or a motor with a brush. The electric motor may be an AC motor such as a three-phase-current motor. The reduction gears construct the transmission device for reducing rotation speed of the motor shaft of the electric motor at a predetermined reduction ratio, and transmitting the reduced output torque of the electric motor to the pin rod 9. The reduction gears include a motor gear, a intermediate gear, and a final gear, which are rotatably accommodated in an actuator case 29. The motor gear is secured to the motor shaft of the electric motor. The intermediate gear is engaged with the motor gear. The final gear is engaged with the intermediate gear.

As shown in FIG. 6, the actuator case 29 includes a substantially cylindrical fitting portion 31 fitted to the inner periphery of a sleeve-shaped cylindrical portion 30 integrated with the right wall portion of the polygonal cylindrical portions 6 of the intake manifold 5. A seal member 32 such as an O-ring is provided between the cylindrical portion 30 and the fitting portion 31. The actuator case 29 rotatably supports the output shaft 34 of the actuator 10 via the bearing member 33. The output shaft 34 of the actuator 10 is connected with an end portion of the pin rod 9 on the side of the actuator 10 via a coupling member 35. The coupling member 35 has a fork portion connected with the one end of the pin rod 9 on the left side in FIG. 6. The coupling member 35 has a right end in FIG. 6, and the right end is connected with a fork portion of the output shaft 34 of the actuator 10. The fork portion of the coupling member 35 is loosely fitted to the fork portion of the output shaft 34.

A stopper lever 36 is provided in the vicinity of the fork portion of the pin rod 9 for regulating the valve position at a full close position. A disc-shaped collar 37 is provided to the right wall of the cylindrical portion 6 on the right side of the intake manifold 5 in FIG. 6. The collar 37 is provided to restrict the stopper lever 36 from causing abrasion directly on the intake manifold 5. The collar 37 is formed of resin or resin compound each containing low friction material such as fluorocarbon polymer. In this construction, driving force of the pin rod 9 can be reduced in a condition where the stopper lever 36 directly slides on the intake manifold 5. Therefore, the electric motor can be downsized.

The stopper lever 36 is secured to the outer periphery of the shaft on the side of the actuator 10 with respect to the valve support portions of the valves 1 to 4. The stopper lever 36 includes a full close stopper portion 36 a and a full open stopper portion 36 b. The full close stopper portion 36 a is hooked to a full close stopper member (full close stopper screw) 38 when all the valves 1 to 4 are in the full close position. The full open stopper portion 36 b is hooked to a full open stopper member (full open stopper screw) 39 when all the valves 1 to 4 are in the full open position.

A collar (full close stopper) 91 is insert-molded in the cylindrical portion 30 of the intake manifold 5. The full close stopper member 38 is screwed to a nut 92 through the collar 91. A collar (full open stopper) 93 is insert-molded in the cylindrical portion 30 of the intake manifold 5. The full open stopper member 39 is screwed to a nut 94 through the collar 93. In this structure, all the valves 1 to 4 are in the full close position in a condition where the full close stopper portion 36 a of the stopper lever 36 is hooked to the full close stopper member 38. In addition, all the valves 1 to 4 are in the full open position in a condition where the full open stopper portion 36 b of the stopper lever 36 is hooked to the full open stopper member 39.

The valve actuator device, in particular, the electric motor is controlled in accordance with electricity supply controlled using an engine control unit (ECU). The ECU controls electricity supplied to the electric motor in accordance with an operating condition of the engine 500 such as engine rotation speed, the throttle position, the accelerator position, and a target intake amount. In this operation, the ECU is capable of controlling the positions of all the valves 1 to 4 throughout a valve operation range from the full close position to the full open position through an intermediate position.

When all the valves 1 to 4 are in the full close position, each of the valves 1 to 4 and the wall surface of the intake passage 12 in the housing 7 define a minimum gap therebetween, so that the amount of intake air passing through the intake passages 12 becomes minimum. When all the valves 1 to 4 are in the full open position, each of the valves 1 to 4 and the wall surface of the intake passage 12 in the housing 7 define a maximum gap therebetween, so that the amount of intake air passing through the intake passages 12 becomes maximum.

The pin rod 9 has the other tip end on the opposite side of the actuator 10, and the other tip end of the pin rod 9 is provided with a spring 41 for reducing play. The spring 41 applies force to the pin rod 9 to reduce a gap in the connection in which the output shaft 34 of the actuator 10 is fitted to the coupling member 35. First and second cylindrical sleeves 42 are provided to the outer periphery of the pin rod 9. The spring 41 applies force to the pin rod 9 such that rotation angle of the first cylindrical sleeve 42 relative to the second cylindrical sleeve 42 becomes constant correspondingly to a fitting gap between the first and second cylindrical sleeves 42. A cylindrical portion 43 is a sleeve-shaped member integrally formed with the left wall portion of the cylindrical portion 6 of the intake manifold 5. The spring 41 is accommodated in a space between the cylindrical portion 43 and a cap 44.

Each valve unit defines a rectangular hole 45, which is a through hole extending along the pin rod 9. Each of the valves 1 to 4 has the cylindrical valve shaft 46, which circumferentially define the rectangular hole 45, and a plate-shaped valve member, which radially extends from the valve shaft 46. That is, the valve member extends perpendicularly to the rotation shaft. The rectangular hole 45 of each of the valves 1 to 4 is a through hole straightly extending perpendicularly to the center axis of each intake passage 12 of the housing 7. Each valve shaft 46 axially extends through the rectangular hole 45.

In this embodiment, the pin rod 9 is a shaft formed of metal such as a ferrous material to be in a polygonal shape in cross section. The pin rod 9 is inserted into each rectangular hole 45 of each of the valves 1 to 4. The pin rod 9 has fitting portions (valve support portions) 51 to 54 each supporting corresponding valve shaft 46 at a predetermined mount angle. The shape of each rectangular hole 45 corresponds to the rectangular cross section of the pin rod 9. That is, the shape of each rectangular hole 45 is substantially the same as the rectangular cross section of each of the valve support portions 51 to 54 of the pin rod 9. In this structure, the valves 1 to 4 can be restricted from rotating relatively to the pin rod 9.

The valves 1 to 4 are formed of a resin material such as grass fiber reinforced thermoplastic to be in a predetermined shape. The valves 1 to 4 have a rotation center perpendicularly to the center axis of each housing 7. The valves 1 to 4 are skewered with the pin rod 9 as a single member to construct a rotary valve. The valves 1 to 4 are rotated in the operation range between the full close position and the full open position, so that the valves 1 to 4 open and close the intake passages 12 of the housings 7.

Each valve member of the valves 1 to 4 is in a rectangular shape having the upper and lower sides, which are greater or less than the right and left sides thereof in FIG. 4. The valves 1 to 4 are rotatably accommodated in the housings 7 respectively defining the intake passages 12. Each of the valves 1 to 4 has four corners each having a chamfer being in one of a square shape, an arc shape, and an R shape.

Each valve member of the valves 1 to 4 has the upper periphery having a center portion defining a main opening portion (notch, slit) 47 in a substantially rectangular shape for generating vortex intake flow (tumble flow) in intake air flowing into the combustion chamber of each cylinder of the engine 500. That is, the main opening portion 47 is defined by the upper periphery of each valve member opposed to the upper wall portion 21 of the housing 7. Each valve member of each of the valves 1 to 4 has both sides partially have four sub-openings (notch slit) 48 each having an opening area less than that of the main opening portion 47. Each valve member has a front surface and a back surface. The back surface of the valve member is provided with reinforcing ribs 49 each having the height gradually decreasing from the valve shaft 46 toward the tip end of the valve member.

Each valve shaft 46 provided with each of the valves 1 to 4 is in a substantially cylindrical shape circumferentially surrounding each of the valve support portions 51 to 54 of the pin rod 9. Each valve shaft 46 has both axial ends defining sliding portions (sliding surfaces) slidably supported by the inner periphery of each housing 7 via the two bearings 26, 27.

Each valve shaft 46 is arranged offset from the center axis of each intake passage 12 toward the bottom wall surface. Each valve shaft 46 is arranged offset from the center of each intake passage 12 toward the upstream of the intake air flow. In this structure, each valve shaft 46 is located in the vicinity of the upstream opening of each housing 7, and are located in the vicinity of the lower wall portion 22 of each housing 7. When each of the valves 1 to 4 is in the full open position, the back surface of the valve member of each of the valves 1 to 4 is opposed to the bottom wall surface of the lower wall portion 22 of each housing 7, and defines a minimum gap therebetween.

In addition, when each of the valves 1 to 4 is in the full close position, each valve shaft 46 of each of the valves 1 to 4 is eccentrically located on the lower side in FIG. 2, i.e., on one side of the surface of the valve member extending perpendicular to the thickness direction of the valve member. In this structure, each of the valves 1 to 4 has the valve shaft 46 defining the rotation center on the opposite side of the free end, and construct a cantilever structure.

The pin rod 9 is fitted, e.g., press-inserted into each rectangular hole 45 of each of the valves 1 to 4. The valves 1 to 4 are skewered with the pin rod 9 serving as singular driving shaft integrally supporting the valves 1 to 4. The pin rod 9 straightly extends along the rotation axis, and has a polygonal cross section. The pin rod 9 includes the valve support portions 51 to 54 press-inserted into the inner periphery of each valve shaft 46 of each of the valves 1 to 4. The valve support portions 51 to 54 are provided respectively to the valves 1 to 4 of the valve units.

Specifically, the valve support portion 51 serves as a first fitting portion being press-fitted into the inner periphery of the valve shaft 46 of the valve 1. The valve support portion 51 defines the angle of the valve 1 at a predetermined mount angle θv1. The valve support portion 52 serves as a second fitting portion being press-fitted into the inner periphery of the valve shaft 46 of the valve 2. The valve support portion 52 defines the angle of the valve 2 at a predetermined mount angle θv2. The valve support portion 53 serves as a third fitting portion being press-fitted into the inner periphery of the valve shaft 46 of the valve 3. The valve support portion 53 defines the angle of the valve 3 at a predetermined mount angle θv3. The valve support portion 54 serves as a fourth fitting portion being press-fitted into the inner periphery of the valve shaft 46 of the valve 4. The valve support portion 54 defines the angle of the valve 4 at a predetermined mount angle θv4.

In this embodiment, the intake vortex generator has the following structure in order to absorb variation among throttle positions of all the valves 1 to 4 respectively provided to the cylinders of the engine 500 when being in the full close position, without enhancing rigidity of the pin rod 9. Specifically, the mount angle θv of each of the valves 1 to 4 of each of the valve support portions 51 to 54 of the pin rod 9 is defined correspondingly to load torque applied to each of the valves 1 to 4 toward the valve-open direction (fore-incline direction). The load torque is applied by negative pressure of intake air and the spring 41.

For example, the mount angle θv gradually increase from the distant one of the valve support portions 51 to 54 of the pin rod 9 toward the one of the valve support portions 51 to 54 on the side of the stopper lever 36. The initial valve position corresponds to torsion angle of one of the valve support portions 51 to 54 of the pin rod 9 twisted by load torque caused by intake air and the spring 41. In this structure, the initial valve position corresponding to the torsion angle gradually becomes large from the one distant from the stopper lever 36 to the one in the vicinity of the stopper lever 36.

Specifically, referring to FIG. 1, the mount angle θv of each of the rectangular holes 45 of each valve shaft 46 of each of the valves 1 to 4 gradually increases from the one distant from the stopper lever 36 to the one in the vicinity of the stopper lever 36 in order. The pin rod 9 is inserted into the valve shafts 46 each having the rectangular hole 45.

The rectangular hole 45 of the valve 1 defines the mount angle θv1 with respect to the valve shaft 46 of the valve 1. The rectangular hole 45 of the valve 2 defines the mount angle θv2 with respect to the valve shaft 46 of the valve 2. The rectangular hole 45 of the valve 3 defines the mount angle θv3 with respect to the valve shaft 46 of the valve 3. The rectangular hole 45 of the valve 4 defines the mount angle θv4 with respect to the valve shaft 46 of the valve 4. The mount angles θv of the rectangular holes 45 satisfy: θv1<θv2<θv3<θv4.

For example, one side of each of the rectangular holes 45 of each of the valves 1 to 4 is 4 mm. The mount angle θv1 of the rectangular hole 45 of the valve 1, which is the outermost from the stopper lever 36, is reference angle A deg. The valve 2 is the second one from the outermost valve 1. The mount angle θv2 of the rectangular hole 45 of the valve 2, which is adjacent to the outermost valve 1, is an angle (A+α) deg. The valve 3 is secondarily in the vicinity of the stopper lever 36. The mount angle θv3 of the rectangular hole 45 of the valve 3, which is adjacent to the innermost valve 4, is an angle (A+2α) deg. The valve 3 is most close to the stopper lever 36. The mount angle θv4 of the rectangular hole 45 of the valve 4, which is the innermost one, is an angle (A+3α) deg. The angle α is 2 deg. The angle α is determined in dependence upon the distance between the stopper lever 36 and the axial center of each of the valves 1 to 4. In addition, the angle α is defined in dependence upon the length of each side of the rectangular hole 45.

In this embodiment, the angle between the inner surface of the rectangular hole 45 of one of the valves 1 to 4 and the valve surface of the one of the valves 1 to 4 is different from the angle between the inner surface of the rectangular hole 45 of another one of the valves 1 to 4 and the valve surface of the other one of the valves 1 to 4. In manufacturing this structure, four rectangular pipes may be arranged at angles relatively different from each other, and the four rectangular pipes may be insert-molded in four of the valve shafts 46 respectively to define the rectangular holes 45 in the valves 1 to 4.

The pin rod 9 having the polygonal cross section may not be smoothly rotated in a structure in which each bearing hole 25 of each bearing portion of the housing 7 directly supports the pin rod 9. Therefore, the valve shafts 46 of the valves 1 to 4 cover the pin rod 9, and the outer circumferential peripheries of the valve shafts 46 are rotatably supported by the housing 7 via the bearings 26, 27. The intake manifold 5, the housing 7, and the valves 1 to 4 are formed of thermoplastic resin, which is preferably polyamide resin (PA), unsaturated polyester resin (UP), polyphenylene sulfide (PPS), polybutylene terephthalate (PBT), or the like, in view of thermostability and mechanical strength.

The valves 1 to 4 are in the full close position when the engine 500 is cool in a start condition or when the vehicle is in an idling condition where the amount of intake air is small. When the valves 1 to 4 are in the full close position, each of the valves 1 to 4 is inclined at the predetermined angle toward the valve-open direction with respect to the axis of each intake passage 12.

The valves 1 to 4 are in the full-open position when the engine 500 is operated at middle or high rotation speed. When the valves 1 to 4 are in the full open position, the front and back surfaces of each of the valves 1 to 4 extend substantially along the axis of each intake passage 12. When the engine 500 is operated at the low rotation speed and a large amount of intake air is required, the valves 1 to 4 may be controlled at an intermediate position in which the valves 1 to 4 are rotated slightly from the full close position toward the valve-open direction.

Next, operations and effects of the intake vortex generator are described with reference to FIGS. 1 to 6.

The ECU controls electricity supplied to the electric motor in a normal operating condition where a large amount of intake air is required and the engine 500 is heated. In this condition, the electric motor rotates the valves 1 to 4 toward the valve-open direction. Thus, the electric motor controls all the valves 1 to 4 at the full open position.

In this condition, intake air flows from the intake passages 11 of the intake manifold 5 of the engine 500 into the intake passages 12 of the housings 7 of the valve units through the inlets of the housings 7. The intake air further flows from the outlets of the housings 7 into the intake ports 13 of the cylinder head 8 of the engine 500 straightly through the housings 7. The intake air flows from the intake valves into the combustion chambers of the engine 500 after passing through the intake ports 13. In this condition, each combustion chamber does not generate therein intake vortex flow (vertical tumble flow).

Alternatively, the ECU also controls electricity supplied to the electric motor in a starting operation or in an idling condition where the amount of intake air is small and the engine 500 is cold. In this condition, the electric motor rotates the valves 1 to 4 toward the valve-close direction. Thus, the electric motor controls all the valves 1 to 4 at the full close position.

In this condition, intake air flows from the intake passages 11 of the intake manifold 5 of the engine 500 into the intake passages 12 of the housings 7 through the inlets of the housings 7. The intake air passes substantially only through the main opening portions 47, and enters into upper regions of the intake ports 13 through the outlets of the housings 7. The intake air flows along the upper wall surface of the intake ports 13. The intake air flows into the combustion chambers of the engine 500 through the intake valves after passing along the upper wall surface of the intake ports 13. In this condition, each combustion chamber generates therein tumble flow, thereby enhancing the combustion efficiency therein in the starting operation or in the idling condition of the engine 500. Thus, fuel consumption is reduced, and emission such as hydrocarbon (HC) can be reduced.

In this structure, the upper peripheries of the valves 1 to 4 define the main opening portions 47, and fuel such as gasoline may accumulate around the valves 1 to 4. When fuel accumulates around the valves 1 to 4, and the accumulating fuel flows into the combustion chambers due to, for example, inclination of the vehicle, the combustion chambers may cause incomplete combustion.

In the intake vortex generator, the combustion efficiency can be enhanced in the combustion chambers of the cylinders of the engine 500 by generating vortex flow in intake air entering the combustion chambers of the cylinders of the engine 500 in the starting operation or in the idling condition of the engine 500. The intake vortex generator has the following structure to generate tumble flow in the combustion chambers in the condition where the amount of intake air is small and the engine 500 is cold. When the valves 1 to 4 are in the full close position, sub-intake air flow passes into each intake port 13 through four of the sub-openings 48 in each of the valves 1 to 4, thereby canceling main intake air flow passing through the main opening portions 47 of the valves 1 to 4 and a part of main intake air flow, which turns to return around the main opening portions 47. In this operation, fuel can be restricted from accumulating around the valves 1 to 4.

The ECU also controls electricity supplied to the electric motor when an ignition switch is turned OFF. Thus, the electric motor controls all the valves 1 to 4 at the intermediate position in which the valves 1 to 4 are rotated slightly from the full close position toward the valve-open direction. The ECU terminates supplying of electricity to the electric motor when all the valves 1 to 4 are rotated at the intermediate position.

In this condition, the spring 41 applies force to reduce the gap in the connection between the output shaft 34 of the actuator 10 and the coupling member 35. Thus, all the valves 1 to 4 are balanced at the position inclined relative to the intermediate position toward the valve-open direction correspondingly to the gap defining backlash between the motor gear and the intermediate gear in the reduction gears, or correspondingly to the gap defining backlash between the intermediate gear and the final gear in the reduction gears.

When the engine 500 is operated at the low rotation speed and a large amount of intake air is required, all the valves 1 to 4 may be controlled at the intermediate position by supplying electricity to the electric motor to generate tumble flow, even in a condition where the engine 500 is operated. In this operation, tumble flow is generated with increase in the amount of intake air flowing into the combustion chambers of the engine 500. Therefore, combustion efficiency is enhanced in the combustion chambers when the engine 500 is operated at the low rotation speed, so that fuel consumption is reduced, and emission such as hydrocarbon (HC) can be reduced.

Next, effects of this embodiment are described.

Referring to FIGS. 2, 4, when the valves 1 to 4 are in the full close position under operation of the engine 500, intake air applies negative pressure to the back surface of each of the valves 1 to 4 in the intake vortex generator. In this condition, each of the valves 1 to 4 is applied with bending moment, which is caused by load torque, around the valve shaft 46 of each of the valves 1 to 4 toward the valve-open direction indicated by the arrow in FIG. 2. The valve support portions 51 to 54 of the pin rod 9, which is fixed to the valve shafts 46 of the valves 1 to 4, is twisted correspondingly to the load torque. The valve support portions 51 to 54 of the pin rod 9 are significantly twisted in the cantilever-structure in this embodiment.

Furthermore, in this embodiment, the spring 41 is provided to the other axial end of the pin rod 9 on the opposite side of the actuator 10 to bias the pin rod 9 to reduce the gap in the connection between the output shaft 34 of the actuator 10 and the coupling member 35. In this structure, the spring 41 applies load torque to the valves 1 to 4 to generate bending moment around the valve shafts 46 toward the valve-open direction. Thus, the pin rod 9 is twisted correspondingly to the load torque.

When the pin rod 9 applies load torque to the valve member of each of the valves 1 to 4 being in the full close position, the valve support portions of the pin rod 9 are respectively twisted by torsion angles different from each other. In this condition, the angles (full-close angles) of the valves 1 to 4, which are in the full close position, deviate from each other. That is, the full-close angles of the valves 1 to 4, which are in the full close position, widely vary among the cylinders of the engine 500. Consequently, the main intake flow passing through the main opening portions 47 vary among the cylinders, and as a result, leakage of intake air also vary among the cylinders.

The torsion angles of the valve support portions 54 to 51 of the pin rod 9 become gradually large from the valve support portion 54 of the valve 4, which is in the vicinity of the stopper lever 36, to the valve support portion 51 of the valve 1, which is most distant from the stopper lever 36 in order. The opening area of the valve 4, which is innermost to the stopper lever 36 in the full close position, is defined as a reference opening area. As the distance from the stopper lever 36 becomes large, the opening areas of the valves 3 to 1 become large in this order compared with the reference angle when being in the full close position. That is, as the distance from the stopper lever 36 becomes large, the valves 3 to 1 are inclined gradually toward the valve-open direction in this order, when being in the full close position. As the distance from the stopper lever 36 becomes large, the opening areas of the main opening portions 47 of the valves 3 to 1 become large in this order when the valves 1 to 4 are in the full close position. Therefore, as the distance from the stopper lever 36 becomes large, the main intake air flows passing through the main opening portions 47 of the valves 4 to 1 become small in this order.

As the distance from the stopper lever 36 becomes large, the gaps respectively between the upper end surfaces of the valves 4 to 1 and the surfaces of the upper wall portions 21 of the housings 7 becomes large. Consequently, as the distance from the stopper lever 36 becomes large, leakage of intake air increases when the valves 4 to 1 are in the full close position. Accordingly, the effect of the intake vortex generator cannot be properly produced. That is, fuel consumption and emission of hydrocarbon may not be reduced, even the intake vortex generator is provided. Thus, the engine performance may be lowered.

Therefore, in the intake vortex generator provided to the integrated valve device, the mount angles θv1 to θv4 of the valve support portions 51 to 54 of the valves 1 to 4, which are correspondingly provided to the valve support portions 51 to 54 of the pin rod 9, gradually increase in this order toward the stopper lever 36. Specifically, referring to FIG. 1, the mount angles θv1 to θv4 of the rectangular holes 45 of the valve shafts 46 of the valves 1 to 4 gradually increase from the mount angle θv1 distant from the stopper lever 36 to the mount angle θv4 in the vicinity of the stopper lever 36 in order.

The initial valve position corresponds to the torsion angle of one of the valve support portions 51 to 54 of the pin rod 9 twisted by load torque caused by intake air and the spring 41. In this structure, the initial valve position is set to gradually become large from the one distant from the stopper lever 36 to the one in the vicinity of the stopper lever 36. Even when load torque is applied to the valves 1 to 4 toward the valve-open direction differently from each other, the positions of all the valves 1 to 4 are set to be substantially equivalent to each other when being in the full close position.

In this structure, variation in the full close positions of the valves 1 to 4 can be reduced, so that variation in valve openings among the cylinders of the engine 500 can be reduced, without decreasing rigidity of the pin rod 9. Thus, variation among the main intake flows passing through the main opening portions 47 of the valves 1 to 4 can be reduced, so that variation among the main intake flows entering the cylinders of the engine 500 can be reduced. In addition, variation in leakage of intake air flows among the cylinders of the engine 500 can be reduced in a condition where the valves 1 to 4 are in the full close position. Therefore, the engine performance can be maintained without upsizing both the pin rod 9 and the valve shafts 46 and without increasing in manufacturing cost.

In this structure, rigidity of the pin rod 9 need not be enhanced, so that the diameter of the pin rod 9 need not be increased. Thus, the rectangular holes 45 of the valves 1 to 4 and the valve shafts 46, which respectively surround the rectangular holes 45, need not be upsized. Thus, manufacturing cost can be reduced.

Furthermore, weight of the valves 1 to 4 and the pin rod 9 need not increase, so that vibration resistance of the valves 1 to 4 can be maintained. In this structure, even when vibration is transmitted from the vehicle body and the engine 500 to the intake manifold 5 or the housing 7, and/or pulsation in pressure of intake air passing through the intake duct is transmitted to the intake manifold 5 or the housing 7, the valves 1 to 4 do not intensely chatter. Thus, the valves 1 to 4 and the housings 7 can be protected from causing abnormal ablation.

Second Embodiment

In this embodiment, as shown in FIGS. 7A to 7C, the pin rod 9 includes the valve support portions 51 to 54 each having the axial section in a polygonal shape such as a rectangular shape. A connecting portion 55 is provided between adjacent two of the valve support portions 51, 52, thereby connecting the valve support portions 51, 52. A connecting portion 56 is provided between adjacent two of the valve support portions 52, 53, thereby connecting the valve support portions 52, 53. A connecting portion 57 is provided between adjacent two of the valve support portions 53, 54, thereby connecting the valve support portions 53, 54. The connecting portions 55 to 57 respectively extend axially through the shaft through holes 15 defined in the cylindrical portions 6 of the intake manifold 5. The outer diameter of each of the connecting portions 55 to 57 is less than the outer diameter of each of the valve support portions 51 to 54.

In this embodiment, the intake vortex generator has the following structure in order to absorb variation among throttle positions of all the valves 1 to 4 respectively provided to the cylinders of the engine 500 when being in the full close position, without enhancing rigidity of the pin rod 9. Specifically, the mount angle θv of each of the valve support portions 51 to 54 of the pin rod 9 is defined correspondingly to load torque applied to each of the valves 1 to 4 in the valve-open direction (fore-incline direction). The load torque is applied by negative pressure of intake air and the spring 41. The stopper lever 36 is provided to the end of the stopper lever 36 on the right side in FIGS. 3, 6. The mount angle θv, for example, gradually increase from the one of the valve support portions 51 to 54 of the pin rod 9 distant from the stopper lever 36 toward the one of the valve support portions 51 to 54 on the side of the stopper lever 36.

In this structure, the positions of all the valves 1 to 4 are set to be substantially equivalent to each other when being in the full close position.

Referring to FIG. 7, each of the valve support portions 51 to 54 has insertion surfaces relative to the wall surfaces defining the rectangular holes 45. The mount angle θs of each of insertion surfaces of each of the valve support portions 51 to 54 of each of the valves 1 to 4 gradually increases from the one distant from the stopper lever 36 to the one in the vicinity of the stopper lever 36 in order. The pin rod 9 has the valve support portions 51 to 54 respectively having the insertion surfaces inclined at the mount angles θs different from each other. The pin rod 9 is inserted into the rectangular hole 45 of the valve shafts 46 of the valves 1 to 4.

The insertion surface of the valve support portion 51 is inclined at the mount angle θs1. The insertion surface of the valve support portion 52 is inclined at the mount angle θs2. The insertion surface of the valve support portion 53 is inclined at the mount angle θs3. The insertion surface of the valve support portion 54 is inclined at the mount angle θs4. The mount angles θs of the insertion surfaces of the valve support portions 51 to 54 satisfy: θs1<θs2<θs3<θs4.

For example, one side of each of the rectangular holes 45 of each of the valves 1 to 4 is 4 mm. The mount angle θs1 of the insertion surface of the valve support portion 51, which is the outermost from the stopper lever 36, is reference angle A deg. The valve support portion 52 is the second one from the valve support portion 51. The mount angle θs2 of the insertion surface of the valve support portion 52, which is adjacent to the valve support portion 51, is an angle (A+α) deg. The valve support portion 53 is secondarily in the vicinity of the stopper lever 36. The mount angle θs3 of the insertion surface of the valve support portion 53, which is adjacent to the innermost valve support portion 54, is an angle (A+2α) deg. The valve support portion 54 is in the most vicinity of the stopper lever 36. The mount angle θs4 of the insertion surface of the valve support portion 54, which is adjacent to the valve support portion 53, is an angle (A+3α) deg. The angle α is 2 deg. The angle α is determined in dependence upon the distance between the stopper lever 36 and the axial center of each of the valves 1 to 4. In addition, the angle α is defined in dependence upon each side of the rectangular hole 45 and each side of the valve support portions 51 to 54. The structure in this embodiment can produce an effect similarly to the first embodiment.

Third Embodiment

As shown in FIG. 8, in this embodiment, each valve member of each of the valves 1 to 4 has a pin rod peripheral portion 61 in the vicinity of each valve shaft 46. Each valve member has the back surface provided with reinforcing ribs 62 each extending from the valve shaft 46 toward the pin rod peripheral portion 61. In this embodiment, the pin rod peripheral portion 61 and the reinforcing ribs 62 on the backside of the pin rod peripheral portion 61 construct a valve thick portion 63 having the thickness greater than the thickness of the upper end portion of the valve member. The reinforcing ribs 62, which are provided on the backside of the pin rod peripheral portion 61, are substantially the same in the height thereof.

In this embodiment, the intake vortex generator has the following structure in order to absorb variation among throttle positions of all the valves 1 to 4 respectively provided to the cylinders of the engine 500 when being in the full close position, without enhancing rigidity of the pin rod 9. Specifically, rigidity of the pin rod peripheral portion 61 of each of the valves 1 to 4 is defined correspondingly to load torque applied to each of the valves 1 to 4 in the valve-open direction (fore-incline direction). The load torque is applied by negative pressure of intake air and the spring 41. The stopper lever 36 is provided to the end of the stopper lever 36 on the right side in FIGS. 3, 6. Rigidity of the valve thick portion 63 of each of the valves 1 to 4, for example, gradually decrease from the one distant from the stopper lever 36 toward the one on the side of the stopper lever 36.

In this structure, the positions of all the valves 1 to 4 are set to be substantially equivalent to each other when being in the full close position.

Specifically, referring to FIG. 8, the thickness Tv of the valve thick portion 63 of each of the valves 1 to 4 gradually decreases from the one distant from the stopper lever 36 toward the one in the vicinity of the stopper lever 36 in order. The pin rod 9 is inserted into the valve shafts 46 each having the rectangular hole 45.

The valve thick portion 63 of the valve 1, which is most distant from the stopper lever 36, has the thickness Tv1. The valve thick portion 63 of the valve 2, which is secondarily distant from the stopper lever 36, has the thickness Tv2. The valve thick portion 63 of the valve 3, which is in the secondarily vicinity of the stopper lever 36, has the thickness Tv3. The valve thick portion 63 of the valve 4, which is in the most vicinity of the stopper lever 36, has the thickness Tv4. The thickness Tv of the valve thick portion 63 of the valves 1 to 4 satisfy: Tv1>Tv2>Tv3>Tv4.

Rigidity of the valve thick portions 63, in particular, rigidity of the pin rod peripheral portions 61 is enhanced correspondingly to the load torque applied respectively to the valve member of the valves 1 to 4. In this structure, even when load torque is applied to the valves 1 to 4 toward the valve-open direction differently from each other, the angles of the valve support portions 51 to 54 are substantially equivalent to each other in the pin rod 9 when being in the full close position. Thus, the positions of all the valves 1 to 4 are set to be substantially equivalent to each other when being in the full close position. The structure in this embodiment can produce an effect similarly to the first embodiment.

Fourth Embodiment

As shown in FIGS. 9, 10, in this embodiment, the intake vortex generator has the following structure in order to absorb variation among throttle positions of all the valves 1 to 4 of the cylinders of the engine 500 when being in the full close position, without enhancing rigidity of the pin rod 9. Specifically, the opening area of the main opening portion 47, which is located on the upper end periphery opposed to the wall surface of the upper wall portion 21 of the housing 7, is defined correspondingly to load torque applied to each of the valves 1 to 4 in the valve-open direction (fore-incline direction). The load torque is applied by negative pressure of intake air and the spring 41.

The stopper lever 36 is provided to the end of the stopper lever 36 on the right side in FIGS. 3, 6. The opening area of the main opening portion 47 of each of the valves 1 to 4, for example, gradually increase from the one distant from the stopper lever 36 toward the one on the side of the stopper lever 36.

Specifically, referring to FIG. 9, the height (main opening height) Hv of the main opening portion 47 of each of the valves 1 to 4 gradually increases from the one distant from the stopper lever 36 toward the one in the vicinity of the stopper lever 36 in order. The pin rod 9 is inserted into the valve shafts 46 each having the rectangular hole 45.

The main opening height Hv of the main opening portion 47 of the valve 1, which is most distant from the stopper lever 36, has the height Hv1. The main opening height Hv of the main opening portion 47 of the valve 2, which is secondarily distant from the stopper lever 36, has the height Hv2. The main opening height Hv of the main opening portion 47 of the valve 3, which is in the secondarily vicinity of the stopper lever 36, has the height Hv3. The main opening height Hv of the main opening portion 47 of the valve 4, which is in the most vicinity of the stopper lever 36, has the height Hv4. The main opening height Hv of the main opening portion 47 of the valves 1 to 4 satisfy: Hv1<Hv2<Hv3<Hv4.

Even when load torque is applied to the valves 1 to 4 toward the valve-open direction differently from each other, the opening areas of the main opening portions 47 of all the valves 1 to 4 are substantially equivalent to each other when being in the full close position. The structure in this embodiment can produce an effect similarly to the first embodiment.

Fifth Embodiment

As shown in FIG. 11, in this embodiment, the intake manifold 5 has a double-pipe structure including the cylindrical portions 6 and the housings 7. The cylindrical portions 6 respectively have therein the fitting holes 14. The housings 7 are respectively accommodated in the cylindrical portions 6, and respectively have therein the intake passages 12.

Each of the housings 7 has a housing thick portion 72, which is located in the vicinity of each of the valves 1 to 4, and housing thin portions 71 being located in the upstream and the downstream of the housing thick portion 72. The housing thick portion 72 has the thickness greater than that of each of the housing thin portions 71. The housing thick portion 72 is formed of resin integrally with the upper wall portion 21 of each housing 7.

A reference line X is in parallel with an average flow of intake air passing through each intake passage 12. Each housing thick portion 72 of each housing 7 has a protrusion 73 projected from the reference line X toward the valve shaft 46 defining the rotation center of each of the valves 1 to 4. That is, each protrusion 73 is projected to reduce the flow area of each intake passage 12.

The protrusion 73 of each of the housings 7 is defined in the surface of the upper wall portion 21 of the housing 7 partially with respect to both the backward and forward direction and rightward and leftward direction of the housing 7. The protrusion 73 protrudes in the direction to reduce the opening area of the main opening portion 47 on the upper end surface of the valve member of each of the valves 1 to 4. That is, the protrusion 73 extends to thrust into the main opening portion 47.

In addition, when each of the valves 1 to 4 is in the full close position, the tip end surface of the protrusion 73 is opposed to the upper end surface of the valve members of each of the valves 1 to 4 at a predetermined distance. The tip end surface of the protrusion 73 defines an opposed surface 74.

When each of the valves 1 to 4 is in the full close position, the opposed surface 74 of each protrusion 73 is opposed to the upper end surface, in particular, the opening end periphery defining the main opening portion 47 of each of the valves 1 to 4 at the predetermined distance. Each opposed surface 74 defines an end periphery projected relative to the upstream wall surface and the downstream wall surface of the intake passage 12, thereby reducing the cross section of each intake passage 12. Each protrusion 73 of each housing thick portion 72 has a tapered step surfaces in the upstream and the downstream of the opposed surface 74.

In this embodiment, the intake vortex generator has the following structure in order to absorb variation among throttle positions of all the valves 1 to 4 respectively provided to the cylinders of the engine 500 when being in the full close position, without enhancing rigidity of the pin rod 9. The upper wall portion 21 has the height Hh, which is the distance between the axial center of each valve shaft 46 defining the rotation center of each of the valves 1 to 4 and the opposed surface 74 of each protrusion 73. In this embodiment, the height Hh is defined correspondingly to load torque applied to each of the valves 1 to 4 in the valve-open direction (fore-incline direction). The load torque is applied by negative pressure of intake air and the spring 41.

The stopper lever 36 is provided to the end of the stopper lever 36 on the right side in FIGS. 3, 6. The height Hh of the upper wall portion 21, for example, gradually increases from the one distant from the stopper lever 36 toward the one on the side of the stopper lever 36.

Specifically, referring to FIG. 11, the height Hh of the upper wall portion 21 gradually increases from the one distant from the stopper lever 36 toward the one in the vicinity of the stopper lever 36 in order. The pin rod 9 is inserted into the valve shafts 46 each having the rectangular hole 45.

The height Hh of the upper wall portion 21 of the valve 1, which is most distant from the stopper lever 36, has the height Hj1. The height Hh of the upper wall portion 21 of the valve 2, which is secondarily distant from the stopper lever 36, has the height Hh2. The height Hh of the upper wall portion 21 of the valve 3, which is in the secondarily vicinity of the stopper lever 36, has the height Hh3. The height Hh of the upper wall portion 21 of the valve 4, which is in the most vicinity of the stopper lever 36, has the height Hh4. The height Hh of the upper wall portion 21 of the valves 1 to 4 satisfy: Hh1<Hh2<Hh3<Hh4.

In this structure, even when load torque is applied to the valves 1 to 4 toward the valve-open direction differently from each other, the opening areas of all the valves 1 to 4 are set to be substantially equivalent to each other when being in the full close position. In this embodiment, the gaps between the upper end surfaces defining the main opening portions 47 of the valves 1 to 4 and the opposed surfaces 74 of the upper wall portions 21 of the housing 7 are substantially equivalent to each other when the valves 1 to 4 are in the full close position. That is, the opening areas of the main opening portions 47 of all the valves 1 to 4 are substantially equivalent to each other. Thus, in this embodiment, the opening areas of all the valves 1 to 4 are substantially equivalent to each other when being in the full close position. The structure in this embodiment can produce an effect similarly to the first embodiment.

Sixth Embodiment

As shown in FIGS. 12A, 12B, in this embodiment, each valve member of each of the valves 1 to 4 has a valve thick portion 64 having the thickness greater than that of a portion thereof on the side of the valve shaft 64 surrounding the pin rod 9. Each valve thick portion 64 has a valve upper end surface 65 opposed to the wall surface defining the opposed surface in the upper wall portion 21 of the housing 7 when the valves 1 to 4 are in the full close position. Each valve upper end surface 65 is opposed to the upper wall portion 21 at a predetermined gap when the valves 1 to 4 are in the full close position. Each valve thick portion 64 has a protrusion 66, which is in a substantially arc shape, and protrudes from a reference line Y, which is in parallel with the valve surface of each of the valves 1 to 4, toward the valve-close direction of each of the valves 1 to 4. Each protrusion 66 of each of the valves 1 to 4 is formed of resin integrally with the upper end periphery of each of the valves 1 to 4 on the opposite side of the valve shaft 64.

Each protrusion 66 of the upper end surface 65 defines a curved surface 67 bent along a locus of the upper end surface 65 of each of the valves 1 to 4 rotative around the valve shaft 64. The upper end surface 65 defines an opposed surface, which is faced to the wall surface of the housing upper wall portion 21 of each housing 7 at a predetermined gap, through a range from the minimum torsion angle of the pin rod 9 to the maximum torsion angle of the pin rod 9 caused by load torque. Each valve member of each of the valves 1 to 4 has a front surface and a back surface. The front surface of the valve member is provided with reinforcing ribs 69 each having the height gradually decreasing from a tip end 68 defining a tip end surface of the protrusion 66 toward the pin rod 9.

In this embodiment, the intake vortex generator has the following structure in order to absorb variation among throttle positions of all the valves 1 to 4 respectively provided to the cylinders of the engine 500 when being in the full close position, without enhancing rigidity of the pin rod 9. Specifically, the protruding length of the protrusion 66 of each of the valves 1 to 4 is defined correspondingly to the maximum torsion angle of the pin rod 9 in the valve support portion 51 of the valve 1 most distant from the stopper lever 36. The torsion of the pin rod 9 is caused by load torque applied from negative pressure of intake air and the spring 41 to each of the valves 1 to 4 in the valve-open direction (fore-incline direction).

In this structure, even when load torque is applied to the valves 1 to 4 toward the valve-open direction differently from each other, the opening areas of all the valves 1 to 4 are set to be substantially equivalent to each other when being in the full close position. The stopper lever 36 is provided to the end of the stopper lever 36 on the right side in FIGS. 3, 6. When the valve 4, which is in the most vicinity of the stopper lever 36, is in the full close position, the opening area of the valve 4 is an opening area δ1. When the valve 1, which is most distant from the stopper lever 36, is in the full close position, the opening area of the valve 4 is an opening area 62. In the structure of this embodiment, the opening area δ1 is equal to the opening area δ2. In this embodiment, both the upper end surfaces 65 and the curved surfaces 67 of the protrusions 66 of the valves 1 to 4 respectively defines gaps relative to the wall surfaces of the upper wall portions 21 of the housing 7. The opening areas of the gaps are substantially equivalent to each other when the valves 1 to 4 are in the full close position. Thus, in this embodiment, the opening areas of all the valves 1 to 4 are substantially equivalent to each other when being in the full close position. The structure in this embodiment can produce an effect similarly to the first embodiment.

Furthermore, referring to FIG. 12B, each of the housings 7 has a housing thick portion 72, which is located in the vicinity of each of the valves 1 to 4, and the housing thin portion 71 being located in the upstream of the housing thick portion 72. The housing thick portion 72 has the thickness greater than that of the housing thin portion 71. The housing thin portion 71 and the housing thick portion 72 are formed of resin integrally with the upper wall portion 21 of each housing 7.

The reference line X is in parallel with an average flow of intake air passing through each intake passage 12. Each housing thick portion 72 of each housing 7 has a protrusion 75 projected from the reference line X toward the valve shaft 46 defining the rotation center of each of the valves 1 to 4. That is, each protrusion 73 is projected to reduce the flow area of each intake passage 12.

The protrusion 75 of each of the housing thick portions 72 is defined in the surface of the upper wall portion 21 of the housing 7 partially with respect to both the backward and forward direction and rightward and leftward direction of the housing 7. The protrusion 75 protrudes in the direction to reduce the opening area of the main opening portion 47 on the upper end surface of the valve member of each of the valves 1 to 4. That is, the protrusion 75 extends to thrust into the main opening portion 47.

The housing thin portion 71 and the housing thick portion 72 respectively define opposed surfaces 76, 77 each defining a predetermined gap with respect to the upper end surface of each of the valves 1 to 4 when the valves 1 to 4 are in the vicinity of the full close position.

The opposed surface 76 of the housing thin portion 71 defines a predetermined gap relative to the upper end surface of the valve member of at least the valve 4, which is in the most vicinity of the stopper lever 36 (FIGS. 3, 6), when being in the full close position. In particular, the opposed surface 76 of the housing thin portion 71 defines the predetermined gap relative to the opening end periphery defining the main opening portion 47 of the valve 4 when being in the full close position. The opposed surface 76 of each housing thin portion 71 is a substantially flat plane straightly extending from the opposed surface 77 toward the upstream.

The opposed surface 77 of each protrusion 75 defines a predetermined gap relative to the upper end surface of the valve member of at least the valve 1, which is most distant from the stopper lever 36. In particular, the opposed surface 77 of each protrusion 75 defines the predetermined gap relative to the opening end periphery defining the main opening portion 47 of the valve 1. The opposed surface 77 of each protrusion 75 extends from the opposed surface 76, which defines the wall surface in the upstream of the opposed surface 77, toward the valve-open direction of each of the valves 1 to 4. The opposed surface 77 of each protrusion 75 defines a curved surface in a substantially arc-shape along the locus of the upper end surface of the valve member of each of the valves 1 to 4 rotative around the valve shaft 64.

The upper end surface of the valve member of the valve 2, in particular, the opening end periphery defining the main opening portion 47 of the valve 2 is opposed to the opposed surfaces 76, 77 at a predetermined gap. The valve 2 is secondarily distant from the stopper lever 36. The upper end surface of the valve member of the valve 3, in particular, the opening end periphery defining the main opening portion 47 of the valve 3 is opposed to the opposed surfaces 76, 77 at a predetermined gap. The valve 3 is in the secondarily vicinity of the stopper lever 36.

The opposed surfaces 76, 77 of each housing 7 is adapted to being opposed to the upper end surface of each of the valves 1 to 4 at a predetermined gap, through a range from the minimum torsion angle of the pin rod 9 to the maximum torsion angle of the pin rod 9 caused by load torque.

In this embodiment, the intake vortex generator has the following structure in order to absorb variation among throttle positions of all the valves 1 to 4 respectively provided to the cylinders of the engine 500 when being in the full close position, without enhancing rigidity of the pin rod 9. Specifically, the length of the curved surface of the protrusion 75 of each housing 7 is defined correspondingly to the maximum torsion angle of the pin rod 9 in the valve support portion 51 of the valve 1 most distant from the stopper lever 36. The torsion of the pin rod 9 is caused by load torque applied from negative pressure of intake air and the spring 41 to each of the valves 1 to 4 in the valve-open direction (fore-incline direction).

In this structure, even when load torque is applied to the valves 1 to 4 toward the valve-open direction differently from each other, the opening areas of all the valves 1 to 4 are set to be substantially equivalent to each other when being in the full close position. The stopper lever 36 is provided to the end of the stopper lever 36 on the right side in FIGS. 3, 6. When the valve 4, which is in the most vicinity of the stopper lever 36, is in the full close position, the opening area of the valve 4 is an opening area δ1. When the valve 1, which is most distant from the stopper lever 36, is in the full close position, the opening area of the valve 4 is an opening area δ2. In the structure of this embodiment, the opening area δ1 is equal to the opening area δ2.

In this embodiment, the upper end surface of the valve member of each of the valves 1 to 4 defines a gap relative to the opposed surfaces 76, 77. The opening areas of the gaps are substantially equivalent to each other when the valves 1 to 4 are in the full close position. Thus, in this embodiment, the opening areas of all the valves 1 to 4 are substantially equivalent to each other when being in the full close position. The structure in this embodiment can produce an effect similarly to the first embodiment.

MODIFICATION

The intake vortex generator may generate a horizontal swirl flow, instead of the vertical tumble flow described in the above embodiments, for accelerating combustion of mixture gas in the combustion chamber of each cylinder of the engine. The intake vortex generator may generate a squish vortex flow for accelerating combustion of mixture gas in the engine.

The integrated valve device in the above embodiments may be applied to a valve device for controlling intake air flowing into each combustion chamber of the engine. In this case, intake air control valves such as an idle speed control valve and a throttle valve may be provided to the housing of the valve device.

The integrate valve device may be applied to a variable intake control device for an engine having a variable intake valve. The variable intake valve is provided to an engine for variably control a cross section or a length of an intake passage of an intake manifold, in accordance with rotation speed of the engine. The variable intake control device is provided to an engine for enhancing torque of an output shaft of the engine, regardless of the rotation speed of the engine. Specifically, for example, the variable intake valve switches the intake passage to extend the intake passage in the manifold when the rotation speed of the engine is in a low or middle range. Alternatively, the variable intake valve switches the intake passage to shorten the intake passage in the manifold when the rotation speed of the engine is in a high range. The integrated valve device may control an amount of intake air or exhaust gas.

The integrated valve device is not limited to being controlled using the electric actuator including the electric motor and the transmission device such as reduction gears. The integrated valve device may be controlled using an electromagnetic actuator or a negative pressure controlled actuator. In this case, the negative pressure controlled actuator may include a negative pressure control valve being electromagnetically controlled or electrically controlled. The integrated valve device may include a biasing member such as a spring for biasing the valves toward the valve-open direction or the valve-close direction.

The integrated valve device in the above embodiments may be applied to an intake device or an exhaust device of an engine having multiple cylinder banks, instead of being applied to an inline four-cylinder engine. The engine having multiple cylinder banks may be a multicylinder engine such as a v-type engine, a flat-type engine, and a horizontally-opposed engine. The integrated valve device is not limited to have a cantilever-structure. The integrated valve device may have a structure in which valves are supported from both axial ends.

The integrated valve device may have a normally close structure. In this case, the integrated valve device is energized to be in the full open position when the engine is in a normal operation, alternatively, the integrated valve device is de-energized to be in the full close position when the engine is started or the engine is in an idling operation. The integrated valve device may have a normally open structure. In this case, the integrated valve device is de-energized to be in the full open position when the engine is in a normal operation, alternatively, the integrated valve device is energized to be in the full close position when the engine is started or the engine is in an idling operation.

Each of the valves 1 to 4 may be in one of a square shape, a circular shape, an oval shape, an oblong shape, and a polygonal shape, instead of being in a rectangular shape. In this case, the shape of each intake passage 12 of the housing 7 is modified correspondingly to the shape of each of the valves 1 to 4.

In the above embodiments, the housings rotatably accommodate the valves respectively to construct valve units, and the valve units are arranged at predetermined distances in the intake manifold 5 along the pin rod 9. In this structure, the intake manifold 5 serves as a casing. Alternatively, an intake duct or an engine cover may be used as a casing. In this structure, specifically, the intake duct or the engine cover rotatably accommodates the valve units arranged at predetermined distances along the pin rod 9. In this case, the housing 7 can be omitted.

The cross section of the pin rod 9 is not limited to the rectangular shape. The cross section of the pin rod 9 may be any other polygonal shapes.

The above structures of the embodiments can be combined as appropriate.

Various modifications and alternations may be diversely made to the above embodiments without departing from the spirit of the present invention. 

1. An integrated valve device for and internal combustion engine, the integrated valve device comprising: a casing having a plurality of intake passages separately connected with a plurality of cylinders of the internal combustion engine; a plurality of valves each being provided to each of the plurality of intake passages, the plurality of valves each having a through hole extending along a rotation axis; a shaft extending through the through hole along the rotation axis, the plurality of valves being skewered with the shaft; and an actuator for generating driving force to rotate the plurality of valves via the shaft toward one of a valve-open direction and a valve-close direction, wherein the shaft has a plurality of fitting portions respectively supporting the plurality of valves, each of the plurality of valves is at a mount angle with respect to each of the plurality of fitting portions, and the mount angle is determined correspondingly to load torque applied to each of the plurality of valves toward the valve-open direction when being in a full close position.
 2. The integrated valve device according to claim 1, wherein each of the plurality of valves includes a valve shaft and a valve member, the valve shaft is in a substantially cylindrical shape defining the through hole, and the valve member is in a substantially plate shape and radially extends from the valve shaft perpendicularly to the rotation axis.
 3. The integrated valve device according to claim 2, wherein the valve member has a valve surface extending perpendicularly to a thickness direction of the valve member, and the valve member is supported by corresponding one of the plurality of fitting portions via the valve shaft being located eccentrically on one side of to the valve surface.
 4. The integrated valve device according to claim 2, wherein the valve member has an end surface on an opposite side of the valve shaft, and the end surface of the valve member has a notch to define an opening portion for generating vortex flow in intake air flowing to the cylinders of the internal combustion engine.
 5. The integrated valve device according to claim 1, wherein the mount angle between each of the plurality of valves and each of the plurality of fitting portions is determined such that the plurality of valves respectively defines therethrough a plurality of valve openings being substantially equivalent to each other when the plurality of valves is in a full close position.
 6. The integrated valve device according to claim 1, wherein the shaft has one axial end extending out of the plurality of valves, and the one axial end of the shaft includes a stopper portion for limiting a plurality of valve openings of the plurality of valves when being in a full close position.
 7. The integrated valve device according to claim 6, wherein the mount angle increases from that of one of the plurality of valves, which is distant from the stopper portion, toward that of an other of the plurality of valves, which is in the vicinity of the stopper portion.
 8. The integrated valve device according to claim 6, wherein each of the plurality of fitting portions is in a substantially polygonal shape in cross section, and each of the though holes of the plurality of valves is in a substantially polygonal shape correspondingly to the cross section of each of the plurality of fitting portions.
 9. The integrated valve device according to claim 8, wherein the plurality of valves respectively includes a plurality of valve shafts each being in a substantially cylindrical shape defining the through hole, each of the plurality of valve shafts has the through hole at a predetermined angle, and the predetermined angle increases from that of one of the plurality of valves, which is distant from the stopper portion, toward that of an other of the plurality of valves, which is in the vicinity of the stopper portion.
 10. The integrated valve device according to claim 8, wherein the plurality of valves respectively has the plurality of through holes each being inserted with each of the plurality of fitting portions, which is arranged along the rotation axis of the shaft and is distant at a predetermined distance from each other, each of the plurality of fitting portions has an insertion surface being at a predetermined angle, and the predetermined angle increases from that of one of the plurality of fitting portions, which is distant from the stopper portion, toward that of an other of the plurality of fitting portions, which is in the vicinity of the stopper portion.
 11. The integrated valve device according to claim 1, wherein the actuator has an output shaft connected with one axial end of the shaft.
 12. The integrated valve device according to claim 11, further comprising: a biasing member for biasing the shaft to reduce a gap between the shaft and the output shaft of the actuator, wherein the biasing member is provided to the shaft on an axially opposite side of the actuator.
 13. The integrated valve device according to claim 1, wherein the casing is an intake manifold including a plurality of housings respectively defining the plurality of intake passages rotatably accommodating the plurality of valve members to respectively construct a plurality of valve units, and the plurality of valve units is arranged along an axial direction of the shaft and is respectively distant at a predetermined distance from each other.
 14. The integrated valve device according to claim 1, wherein the shaft is a rotation axis defining a rotation center of the plurality of valves.
 15. The integrated valve device according to claim 1, wherein the plurality of fitting portions is respectively inserted in the plurality of through holes of the plurality of valves, which is axially distant at a predetermined distance from each other.
 16. An integrated valve device for and internal combustion engine, the integrated valve device comprising: a casing having a plurality of intake passages separately connected with a plurality of cylinders of the internal combustion engine; a plurality of valves each being provided to each of the plurality of intake passages, the plurality of valves each having a through hole extending along a rotation axis; a shaft extending through the through hole along the rotation axis, the plurality of valves being skewered with the shaft; and an actuator for generating driving force to rotate the plurality of valves via the shaft toward one of a valve-open direction and a valve-close direction, wherein the shaft has a plurality of fitting portions respectively supporting the plurality of valves at mount angles, each of the plurality of valves includes a valve shaft and a valve member, the valve shaft is in a substantially cylindrical shape defining the through hole, the valve member is in a substantially plate shape and radially extends from the valve shaft perpendicularly to the rotation axis, and the valve member of each of the plurality of valves has rigidity, which is determined correspondingly to load torque applied to each of the plurality of valves toward the valve-open direction when being in a full close position.
 17. The integrated valve device according to claim 16, wherein the valve member has a valve surface extending perpendicularly to a thickness direction of the valve member, and the valve member is supported by corresponding one of the plurality of fitting portions via the valve shaft being located eccentrically on one side of to the valve surface.
 18. The integrated valve device according to claim 16, wherein the valve member has an end surface on an opposite side of the valve shaft, and the end surface of the valve member has a notch to define an opening portion for generating vortex flow in intake air flowing to the cylinders of the internal combustion engine.
 19. The integrated valve device according to claim 16, wherein the shaft has one axial end extending out of the plurality of valves, and the one axial end of the shaft includes a stopper portion for limiting a plurality of valve openings of the plurality of valves when being in the full close position.
 20. The integrated valve device according to claim 19, wherein the plurality of the valve members respectively has a plurality of thick portions each being on a side of the valve shaft, each of the plurality of thick portions has a predetermined thickness, and the predetermined thickness decreases from that of one of the plurality of thick portions, which is distant from the stopper portion, toward that of an other of the plurality of thick portions, which is in the vicinity of the stopper portion.
 21. The integrated valve device according to claim 16, wherein each of the plurality of fitting portions is in a substantially polygonal shape in cross section, and each of the though holes of the plurality of valves is in a substantially polygonal shape correspondingly to the cross section of each of the plurality of fitting portions.
 22. The integrated valve device according to claim 16, wherein the actuator has an output shaft connected with one axial end of the shaft.
 23. The integrated valve device according to claim 22, further comprising: a biasing member for biasing the shaft to reduce a gap between the shaft and the output shaft of the actuator, wherein the biasing member is provided to the shaft on an axially opposite side of the actuator.
 24. The integrated valve device according to claim 16, wherein the casing is an intake manifold including a plurality of housings respectively defining the plurality of intake passages rotatably accommodating the plurality of valve members to respectively construct a plurality of valve units, and the plurality of valve units is arranged along an axial direction of the shaft and is respectively distant at a predetermined distance from each other.
 25. The integrated valve device according to claim 16, wherein the shaft is a rotation axis defining a rotation center of the plurality of valves.
 26. The integrated valve device according to claim 16, wherein the plurality of fitting portions is respectively inserted in the plurality of through holes of the plurality of valves, which is axially distant at a predetermined distance from each other.
 27. An integrated valve device for and internal combustion engine, the integrated valve device comprising: a casing having a plurality of intake passages separately connected with a plurality of cylinders of the internal combustion engine; a plurality of valves each being provided to each of the plurality of intake passages, the plurality of valves each having a through hole extending along a rotation axis; a shaft extending through the through hole along the rotation axis, the plurality of valves being skewered with the shaft; and an actuator for generating driving force to rotate the plurality of valves via the shaft toward one of a valve-open direction and a valve-close direction, wherein the shaft has a plurality of fitting portions respectively supporting the plurality of valves at mount angles, each of the plurality of valves includes a valve shaft and a valve member, the valve shaft is in a substantially cylindrical shape defining the through hole, the valve member is in a substantially plate shape and radially extends from the valve shaft perpendicularly to the rotation axis, the valve member has an end surface on an opposite side of the valve shaft, the end surface of the valve member has a notch to define an opening portion for generating vortex flow in intake air flowing to the cylinders of the internal combustion engine, and the opening portion of each of the plurality of valve members has an opening area, which is determined correspondingly to load torque applied to each of the plurality of valve members toward the valve-open direction when being in a full close position.
 28. The integrated valve device according to claim 27, wherein the valve member has a valve surface extending perpendicularly to a thickness direction of the valve member, and the valve member is supported by corresponding one of the plurality of fitting portions via the valve shaft being located eccentrically on one side of to the valve surface.
 29. The integrated valve device according to claim 27, wherein the shaft has one axial end extending out of the plurality of valves, and the one axial end of the shaft includes a stopper portion for limiting a plurality of valve openings of the plurality of valves when being in the full close position.
 30. The integrated valve device according to claim 29, wherein the opening area of the opening portion of each of the plurality of valve members increases from that of one of the plurality of valve members, which is distant from the stopper portion, toward that of an other of the plurality of valve members, which is in the vicinity of the stopper portion.
 31. The integrated valve device according to claim 27, wherein each of the plurality of fitting portions is in a substantially polygonal shape in cross section, and each of the though holes of the plurality of valves is in a substantially polygonal shape correspondingly to the cross section of each of the plurality of fitting portions.
 32. The integrated valve device according to claim 27, wherein the actuator has an output shaft connected with one axial end of the shaft.
 33. The integrated valve device according to claim 32, further comprising: a biasing member for biasing the shaft to reduce a gap between the shaft and the output shaft of the actuator, wherein the biasing member is provided to the shaft on an axially opposite side of the actuator.
 34. The integrated valve device according to claim 27, wherein the casing is an intake manifold including a plurality of housings respectively defining the plurality of intake passages rotatably accommodating the plurality of valve members to respectively construct a plurality of valve units, and the plurality of valve units is arranged along an axial direction of the shaft and is respectively distant at a predetermined distance from each other.
 35. The integrated valve device according to claim 27, wherein the shaft is a rotation axis defining a rotation center of the plurality of valves.
 36. The integrated valve device according to claim 27, wherein the plurality of fitting portions is respectively inserted in the plurality of through holes of the plurality of valves, which is axially distant at a predetermined distance from each other.
 37. An integrated valve device for and internal combustion engine, the integrated valve device comprising: a casing having a plurality of intake passages separately connected with a plurality of cylinders of the internal combustion engine; a plurality of valves each being provided to each of the plurality of intake passages, the plurality of valves each having a through hole extending along a rotation axis; a shaft extending through the through hole along the rotation axis, the plurality of valves being skewered with the shaft; and an actuator for generating driving force to rotate the plurality of valves via the shaft toward one of a valve-open direction and a valve-close direction, wherein the shaft has a plurality of fitting portions respectively supporting the plurality of valves at mount angles, each of the plurality of valves includes a valve shaft and a valve member, the valve shaft is in a substantially cylindrical shape defining the through hole, the valve member is in a substantially plate shape and radially extends from the valve shaft perpendicularly to the rotation axis, the casing has a plurality of cylindrical portions each defining therein each of the plurality of intake passages, each of the plurality of cylindrical portions has a wall surface defining a protrusion in the vicinity of the valve member being in a full close position, the protrusion extends to reduce a cross section of each of the plurality of intake passages, and has a tip end defining an opposed surface being faced to an end surface of the valve member being in the full close position, the opposed surface of the protrusion is at a distance from a rotation center of each of the plurality of valve members, and the distance is determined correspondingly to load torque applied to each of the plurality of valve members toward the valve-open direction when the plurality of valve members is in the full close position.
 38. The integrated valve device according to claim 37, wherein the valve member has a valve surface extending perpendicularly to a thickness direction of the valve member, and the valve member is supported by corresponding one of the plurality of fitting portions via the valve shaft being located eccentrically on one side of to the valve surface.
 39. The integrated valve device according to claim 37, wherein the valve member has an end surface on an opposite side of the valve shaft, and the end surface of the valve member has a notch to define an opening portion for generating vortex flow in intake air flowing to the cylinders of the internal combustion engine.
 40. The integrated valve device according to claim 37, wherein the shaft has one axial end extending out of the plurality of valves, and the one axial end of the shaft includes a stopper portion for limiting a plurality of valve openings of the plurality of valves when being in the full close position.
 41. The integrated valve device according to claim 40, wherein the distance increases from that of one of the plurality of valve members, which is distant from the stopper portion, toward that of an other of the plurality of valve members, which is in the vicinity of the stopper portion.
 42. The integrated valve device according to claim 37, wherein each of the plurality of fitting portions is in a substantially polygonal shape in cross section, and each of the though holes of the plurality of valves is in a substantially polygonal shape correspondingly to the cross section of each of the plurality of fitting portions.
 43. The integrated valve device according to claim 37, wherein the actuator has an output shaft connected with one axial end of the shaft.
 44. The integrated valve device according to claim 43, further comprising: a biasing member for biasing the shaft to reduce a gap between the shaft and the output shaft of the actuator, wherein the biasing member is provided to the shaft on an axially opposite side of the actuator.
 45. The integrated valve device according to claim 37, wherein the casing is an intake manifold including a plurality of housings respectively defining the plurality of intake passages rotatably accommodating the plurality of valve members to respectively construct a plurality of valve units, and the plurality of valve units is arranged along an axial direction of the shaft and is respectively distant at a predetermined distance from each other.
 46. The integrated valve device according to claim 37, wherein the shaft is a rotation axis defining a rotation center of the plurality of valves.
 47. The integrated valve device according to claim 37, wherein the plurality of fitting portions is respectively inserted in the plurality of through holes of the plurality of valves, which is axially distant at a predetermined distance from each other.
 48. An integrated valve device for and internal combustion engine, the integrated valve device comprising: a casing having a plurality of intake passages separately connected with a plurality of cylinders of the internal combustion engine; a plurality of valves each being provided to each of the plurality of intake passages, the plurality of valves each having a through hole extending along a rotation axis; a shaft extending through the through hole along the rotation axis, the plurality of valves being skewered with the shaft; and an actuator for generating driving force to rotate the plurality of valves via the shaft toward one of a valve-open direction and a valve-close direction, wherein the shaft has a plurality of fitting portions respectively supporting the plurality of valves at mount angles, each of the plurality of valves includes a valve shaft and a valve member, the valve shaft is in a substantially cylindrical shape defining the through hole, the valve member is in a substantially plate shape and radially extends from the valve shaft perpendicularly to the rotation axis, the valve member of each of the plurality of valves has an end surface on an opposite side of the valve shaft, the valve member has a protrusion in the vicinity of the end surface, the protrusion is in a substantially arc shape along a locus of the valve member being rotatable, the valve member has a valve surface on a side of the valve shaft with respect to the protrusion, the protrusion of the valve member extends toward the valve-close direction relative to the valve surface, the protrusion has a length with respect to the valve-close direction, and the length of the protrusion is determined correspondingly to a maximum angle of torsion caused in the shaft by load torque applied to the plurality of valves toward the valve-open direction when being in the full close position.
 49. The integrated valve device according to claim 48, wherein the valve member has a valve surface extending perpendicularly to a thickness direction of the valve member, and the valve member is supported by corresponding one of the plurality of fitting portions via the valve shaft being located eccentrically on one side of to the valve surface.
 50. The integrated valve device according to claim 48, wherein the valve member has an end surface on an opposite side of the valve shaft, and the end surface of the valve member has a notch to define an opening portion for generating vortex flow in intake air flowing to the cylinders of the internal combustion engine.
 51. The integrated valve device according to claim 48, wherein each of the plurality of fitting portions is in a substantially polygonal shape in cross section, and each of the though holes of the plurality of valves is in a substantially polygonal shape correspondingly to the cross section of each of the plurality of fitting portions.
 52. The integrated valve device according to claim 48, wherein the actuator has an output shaft connected with one axial end of the shaft.
 53. The integrated valve device according to claim 52, further comprising: a biasing member for biasing the shaft to reduce a gap between the shaft and the output shaft of the actuator, wherein the biasing member is provided to the shaft on an axially opposite side of the actuator.
 54. The integrated valve device according to claim 48, wherein the casing is an intake manifold including a plurality of housings respectively defining the plurality of intake passages rotatably accommodating the plurality of valve members to respectively construct a plurality of valve units, and the plurality of valve units is arranged along an axial direction of the shaft and is respectively distant at a predetermined distance from each other.
 55. The integrated valve device according to claim 48, wherein the shaft is a rotation axis defining a rotation center of the plurality of valves.
 56. The integrated valve device according to claim 48, wherein the plurality of fitting portions is respectively inserted in the plurality of through holes of the plurality of valves, which is axially distant at a predetermined distance from each other.
 57. An integrated valve device for and internal combustion engine, the integrated valve device comprising: a casing having a plurality of intake passages separately connected with a plurality of cylinders of the internal combustion engine; a plurality of valves each being provided to each of the plurality of intake passages, the plurality of valves each having a through hole extending along a rotation axis; a shaft extending through the through hole along the rotation axis, the plurality of valves being skewered with the shaft; and an actuator for generating driving force to rotate the plurality of valves via the shaft toward one of a valve-open direction and a valve-close direction, wherein the shaft has a plurality of fitting portions respectively supporting the plurality of valves at mount angles, each of the plurality of valves includes a valve shaft and a valve member, the valve shaft is in a substantially cylindrical shape defining the through hole, the valve member is in a substantially plate shape and radially extends from the valve shaft perpendicularly to the rotation axis, the casing has a plurality of cylindrical portions each defining therein each of the plurality of intake passages, each of the plurality of cylindrical portions has a wall surface defining each of the plurality of intake passages, the wall surface defines an opposed surface being faced to an end surface of the valve member being in the full close position, the opposed surface of each of the plurality of cylindrical portions extends to an upstream of an intake air along the valve-open direction, the opposed surface is in a substantially arc shape along a locus of the valve member being rotatable, the opposed surface has a length with respect to the valve-open direction, and the length of the opposed surface is determined correspondingly to a maximum angle of torsion caused in the shaft by load torque applied to the plurality of valves toward the valve-open direction when being in the full close position.
 58. The integrated valve device according to claim 57, wherein the valve member has a valve surface extending perpendicularly to a thickness direction of the valve member, and the valve member is supported by corresponding one of the plurality of fitting portions via the valve shaft being located eccentrically on one side of to the valve surface.
 59. The integrated valve device according to claim 57, wherein the valve member has an end surface on an opposite side of the valve shaft, and the end surface of the valve member has a notch to define an opening portion for generating vortex flow in intake air flowing to the cylinders of the internal combustion engine.
 60. The integrated valve device according to claim 57, wherein each of the plurality of fitting portions is in a substantially polygonal shape in cross section, and each of the though holes of the plurality of valves is in a substantially polygonal shape correspondingly to the cross section of each of the plurality of fitting portions.
 61. The integrated valve device according to claim 57, wherein the actuator has an output shaft connected with one axial end of the shaft.
 62. The integrated valve device according to claim 61, further comprising: a biasing member for biasing the shaft to reduce a gap between the shaft and the output shaft of the actuator, wherein the biasing member is provided to the shaft on an axially opposite side of the actuator.
 63. The integrated valve device according to claim 57, wherein the casing is an intake manifold including a plurality of housings respectively defining the plurality of intake passages rotatably accommodating the plurality of valve members to respectively construct a plurality of valve units, and the plurality of valve units is arranged along an axial direction of the shaft and is respectively distant at a predetermined distance from each other.
 64. The integrated valve device according to claim 57, wherein the shaft is a rotation axis defining a rotation center of the plurality of valves.
 65. The integrated valve device according to claim 57, wherein the plurality of fitting portions is respectively inserted in the plurality of through holes of the plurality of valves, which is axially distant at a predetermined distance from each other. 